Omega-3 oils are widely noted in the published literature for their beneficial effects on ocular health, and certain omega-3 fatty acids are known to be significant components of the mammalian eye. See, e.g., Insight, October-December; 33(4): 20-5 (2008). A majority of omega-3 oil products are formulated as soft or hard gel capsules filled with omega-3 oil compositions which are intended for oral and systemic delivery of the omega-3 oils. Currently there are no commercial ophthalmic products in US market containing omega-3 oils for ocular surface delivery. Emulsions are typically the preferred dosage form for delivery of oily components to the surface of the eye, in which the oil dispersed in the water phase as droplets typically in the sub-micron range by using surfactants and emulsifiers.
A major hurdle in development of an ophthalmic product containing the omega-3 oils is the chemical stability of the omega-3 components which are susceptible degradation by oxidation and hydrolysis. U.S. Patent Publication Nos. 2007/0265341, 2008/0153909 and 2010/0305045, for example, teach certain omega-3 oil containing compositions, but do not address this stability issue. U.S. 2007/0265341 teaches the use of vitamin E as an antioxidant, but vitamin E is not effective in preserving omega-3 oils as described herein. Thus, there is a need for stable ophthalmic compositions containing omega-3 oils.